Zak
Legend
I'd love to see a picture of your tailed, flashback halfback!It is hard to fish a halfback wrong. My first experience was fishing it on a floating line in the surface film during a hatch and having a massive fish take it right at the surface. The take was insignificant, I thought it was probably an 8-10'' fish and was pleasantly surprised.
Then I started fishing it right at the bank in spring and got lots of takes. Nowadays I tie it as a flashback and think it often gets taken for a boatman pattern. I have used it on every line from floater to Type 7 and it just seems to have universal appeal to fish at all depths.
One of the most surprising results came years ago when Coffeepot Lake still had lots of fish. Fishing the closer at the end of September I used a size 12 Halfback on a Type 6 line in 30-40' of water with most of the line off of the spool. I caught fish after fish and this was back when the fish were big and plentiful. How fish could spot that tiny fly down that deep in such a huge lake has always been a mystery to me.
My pattern is very similar to the one that Zak shows but always has a tail. I use pheasant tail fibers fairly short and splay them out. To keep them that way I use a tiny drop of UV and zap it with a light and I also do the same with the legs to keep them away from the body. If you have watched nymphs swim under water you probably noticed that they don't swim with their legs plastered to their body. And they seem to use their tails to navigate much like the rudder and ailerons on a aircraft. They get taken for live nymphs so often that I'm starting to think I might be on to something!